1. Field of the Invention
The present invention relates to fabric constructions for clothing, and, more particularly, to breathable fabric constructions for substantially predeterminedly shaped clothing items that maintain their basic shape when not being worn.
2. The Prior Art
Outerwear is typically constructed from fabrics or combinations of fabrics that strive to achieve seemingly inconsistent objectives. It is desired that such outerwear be vapor permeable, water repellent, wind obstructing, stain resistant, dimensionally stable, externally durable, and internally comfortable. Vapor permeable membranes and/or tight weaving have been among the compromises needed to permit simultaneous vapor permeability, water repulsion, and wind obstruction. Special fabrics and/or coatings have been among the compromises needed for stain resistance, dimensional stability, external durability, and internal comfort. In particular, for example, the interstices within tightly woven fabric, which must remain open to achieve breathing, tend to become blocked by water proofing and wind blocking treatments.
Boots and handwear, especially gloves, have special problems associated with their construction. A typical boot or glove for inclement weather is constructed from a number of layers, including an outer shell, a waterproofing layer, an insulating layer, and an inner lining. The inner lining is typically a thin, soft material that provides a comfortable surface against the skin of the hand. The insulating layer is generally the thickest layer and provides insulation to hold in warmth from the skin. The waterproofing layer is composed of a material that is both waterproof and breathable so that water is kept out and perspiration is allowed to escape. One such material is manufactured and sold by W. L. Gore & Associates, Inc., Elkton, Md. under the trade designation GORE-TEX.
The shell of a boot has evolved recently from being constructed entirely from leather to a combination of leather and synthetic fabrics, such as nylon, where the leather is generally in the high-wear areas of the shell and the fabrics in the areas that do not see as much wear, such as the upper front. The leather used in boots has a large amount of body, that is, it is dimensionally stable and does not deform extensively. Synthetic fabrics, on the other hand, have little body, little dimensional stability.
During the life of a boot, the fabric portions may flex under stress as much as a million times or more. This can cause seam slippage, the tendency for the stitching to work its way to the edge of a woven material and separate from the material. Consequently, although the stitching is still intact, it is no longer threaded through the weave of the fabric, rendering the seam useless. Material that easily unravels at the edge encourages seam slippage because the weave is looser and, as the edge becomes unraveled, the edge of the material moves closer to the stitching, meaning that the stitching does not have as far to go to slip from the fabric.
Like the fabric portions of the boot, the shell of a glove is generally a woven synthetic material, such as nylon. Portions of the shell's outer surface, for example, at the palm, fingers, and knuckles, are reinforced with natural or synthetic leather panels for improved wear.
In a glove, the result of the multiplicity of layers is that a glove that is not constructed appropriately is very bulky and uncomfortable to wear, especially at places where there are tight curves, such as at the base of the fingers and thumb. The seams between panels of fabric contribute significantly to the bulk and discomfort, so the amount of space allocated for seams, the seam allowance, is kept small, approximately 1/8 inch. This means that normal seaming techniques that prevent unraveling of the edge of the fabric, such as felled and overlock seams, cannot be used because they exceed the small seam allowance. Consequently, there is a problem with unraveling and the associated seam slippage.
Another type of outerwear, body armor shells, also have special problems associated with their construction. Body armor protects the wearer from penetration injuries from bullets, knives, and the like, and generally consists of two components, ballistic plates and a shell. The plates are composed of materials that resist or prevent penetration. One example of such a material is the aramid fiber sold under the trade designation KEVLAR. These materials tend to be sensitive to and need to be protected from moisture in order to retain their penetration-prevention characteristics. To this end, the plates are protected by waterproof fabric covers. Additionally, in order to make the armor wearable in various weather conditions, the covers are made breathable. An example of such a ballistic plate cover is disclosed in U.S. Pat. No. 5,471,906, issued to Bachner, Jr. et al.
The ballistic plates are placed in the shell for wearing. The typical shell is worn like a vest that covers the torso, both front and back. The plates are inserted into pockets inside the shell and held in place typically by flaps held closed by microcatch patches. The shell is made from a synthetic fabric, such as nylon. As discussed above, synthetic fabrics have little dimensional stability and would be stretched and deformed significantly by the weight of the ballistic plates. Also, the weight of the plates poses a problem for the seams of the shell, stressing them severely, especially when the wearer is running and the plates are bouncing around inside the pocket. The stress causes not only seam slippage, but unraveling.
Dimensional stability and the prevention of seam slippage and edge unraveling are typically achieved in the prior art by applying a continuous coating of material that covers substantially the entire inner surface of the shell fabric. A continuous coating has several shortcomings. A continuous coating severely limits the breathability of the shell, negating much of the benefit from the waterproof, breathable layer and making these coated fabrics uncomfortable to wear. Because the coating covers the entire area of the fabric, there are no openings to allow the air to pass through the interstices of the fabric. In some cases, to overcome this weakness, thin coatings and/or coatings made of a softer and weaker material are used. However, these coatings have another problem in that they have a tendency to wash off during laundering. And the thicker coatings have a tendency to stiffen in colder weather, making them uncomfortable to wear.
Another weakness of the continuous coating is related to the lack of breathability. When the coated fabrics are cut to shape in the production process, a vacuum table is used to hold the fabric stable. If the fabric has a low breathability, only a small number of layers can be cut simultaneously because the vacuum generated by the table can reach through only several layers of continuously-coated fabric. If the coated fabric is more breathable, more layers of fabric can be held and cut simultaneously, making the production process more time and cost efficient.
Thus, there is an ongoing need for the improvement of clothing items that have a substantially predetermined shape that is maintained when not being worn, especially for items that includes waterproof, breathable inner layers, in the way that ravel and seam slippage prevention and dimensional stability is provided.